The present invention relates to the improvement of a waterproof electrical connector and more particularly to the improvement of a seal ring employed in a waterproof electrical connector.
In many of the electrical connectors, a male connector housing and a female connector housing are engaged with each other for electrical connection through terminal members installed therein. If such connectors are to be installed at a place where they are subject to rain water, waterproof electrical connectors are used to prevent short circuiting.
One example of such conventional waterproof electrical connectors is shown in FIG. 1, in which a male connector housing 1 is to be engaged with a female connector housing 2. Around the periphery 1a of said male connector housing 1, there is formed an annular enclosure 1b. Said annular enclosure 1b is formed by an annular wall 3 surrounding said outer periphery 1a and an end wall 4 extends radially to connect said annular wall 3 and said outer periphery 1a to define an annular cavity 6. On the other hand, the female connector housing 2 includes an outer periphery 2a and a sleeve 2b extending forwardly of said outer periphery 2a.
When a seal ring 7 of resilient material such as rubber is inserted in said cavity 6, said seal ring 7 fits against the annular enclosure to leave a space 6' inwardly thereof. At the same time, said seal ring is formed with an engaging protrusion 7a in an outer periphery thereof as shown in FIG. 2, said engaging protrusion 7a is squeezed into an engaging window 3a formed in the annular wall 3 of the male connector housing 1 for securing said seal ring 7 within said cavity 6.
FIG. 3a is a sectional view of the seal ring 7 taken along the line III--III of FIG. 2 to show a seal ring 7c which bulges around the inner periphery thereof which press contacts the sleeve 2b of the female connector housing 2. In the prior art as described in the foregoing, said seal ring 7 has a tendancy to turn over inside out at the time of engagement or disengagement of both housings as shown in FIG. 3b. In this way, the positioning of the seal ring 7 within the cavity will not be assured for making the connector waterproof. In order to overcome the shortcoming of the prior art waterproof connector, it is an object of the present invention to provide a seal ring which will not turn over even at the time of engagement or disengagement of the male and female connector housings.